Why Can’t Doctors Identify Killers?

May 27, 2014

Richard A. Friedman

MASS killers like Elliot Rodger teach society all the wrong lessons about the connection between violence, mental illness and guns — and what we should do about it. One of the biggest misconceptions, pushed by our commentators and politicians, is that we can prevent these tragedies if we improve our mental health care system. It is a comforting notion, but nothing could be further from the truth.

And although the intense media attention might suggest otherwise, mass killings — when four or more people are killed at once — are very rare events. In 2012, they accounted for only about 0.15 percent of all homicides in the United States. Because of their horrific nature, however, they receive lurid media attention that distorts the public’s perception about the real risk posed by the mentally ill.

Anyone who watched Elliot Rodger’s chilling YouTube video, detailing his plan for murderous vengeance before he killed six people last week near Santa Barbara, Calif., would understandably conflate madness with violence. While it is true that most mass killers have a psychiatric illness, the vast majority of violent people are not mentally ill and most mentally ill people are not violent. Indeed, only about 4 percent of overall violence in the United States can be attributed to those with mental illness. Most homicides in the United States are committed by people without mental illness who use guns.

Mass killers are almost always young men who tend to be angry loners. They are often psychotic, seething with resentment and planning revenge for perceived slights and injuries. As a group, they tend to avoid contact with the mental health care system, so it’s tough to identify and help them. Even when they have received psychiatric evaluation and treatment, as in the case of Mr. Rodger and Adam Lanza, who killed 20 children and seven adults, including his mother, in Connecticut in 2012, we have to acknowledge that our current ability to predict who is likely to be violent is no better than chance.

Large epidemiologic studies show that psychiatric illness is a risk factor for violent behavior, but the risk is small and linked only to a few serious mental disorders. People with schizophrenia, major depression or bipolar disorder were two to three times as likely as those without these disorders to be violent. The actual lifetime prevalence of violence among people with serious mental illness is about 16 percent compared with 7 percent among people who are not mentally ill.

What most people don’t know is that drug and alcohol abuse are far more powerful risk factors for violence than other psychiatric illnesses. Individuals who abuse drugs or alcohol but have no other psychiatric disorder are almost seven times more likely than those without substance abuse to act violently.

As a psychiatrist, I welcome calls from our politicians to improve our mental health care system. But even the best mental health care is unlikely to prevent these tragedies.

If we can’t reliably identify people who are at risk of committing violent acts, then how can we possibly prevent guns from falling into the hands of those who are likely to kill? Mr. Rodger had no problem legally buying guns because he had neither been institutionalized nor involuntarily hospitalized, both of which are generally factors that would have prevented him from purchasing firearms.

Would lowering the threshold for involuntary psychiatric treatment, as some argue, be effective in preventing mass killings or homicide in general? It’s doubtful.

The current guideline for psychiatric treatment over the objection of the patient is, in most states, imminent risk of harm to self or others. Short of issuing a direct threat of violence or appearing grossly disturbed, you will not receive involuntary treatment. When Mr. Rodger was interviewed by the police after his mother expressed alarm about videos he had posted, several weeks ago, he appeared calm and in control and was thus not apprehended. In other words, a normal-appearing killer who is quietly planning a massacre can easily evade detection.

In the wake of these horrific killings, it would be understandable if the public wanted to make it easier to force treatment on patients before a threat is issued. But that might simply discourage other mentally ill people from being candid and drive some of the sickest patients away from the mental health care system.

We have always had — and always will have — Adam Lanzas and Elliot Rodgers. The sobering fact is that there is little we can do to predict or change human behavior, particularly violence; it is a lot easier to control its expression, and to limit deadly means of self-expression. In every state, we should prevent individuals with a known history of serious psychiatric illness or substance abuse, both of which predict increased risk of violence, from owning or purchasing guns.

But until we make changes like that, the tragedy of mass killings will remain a part of American life.

Richard A. Friedman is a professor of clinical psychiatry and the director of the psychopharmacology clinic at the Weill Cornell Medical College.